Isabela is generally safe for solo female travelers. The area boasts lower crime rates compared to some other regions of Puerto Rico, but as with any destination, it's always wise to maintain personal safety precautions. This can include avoiding isolated areas at night and being aware of your surroundings at all times. The locals are known to be friendly and welcoming, and harassment is not a common issue reported by tourists. Local authorities are typically helpful and efficient. Nevertheless, always keep the basic travel safety rules in mind.